Thus IS is needed to help Senior Managers , Middle Managers, Operational Managers and employees in their day to day activities. There are many types of IS which can help these sectors make decisions the main one is the Decision Support System (DSS). Dan Power defines it as “ an interactive computer-based system or subsystem intended to help decision makers use communications technologies, data, documents, knowledge and/or models to identify and solve problems, complete decision process tasks, and make decisions”.